Broadband radio frequency data communication system using twisted pair wiring

ABSTRACT

A system for distributing broadband signals via twisted pair wiring is disclosed. Various aspects of the system involve use of a broadband signal distribution interface device and/or a broadband line driver. In one aspect, a broadband signal distribution interface device includes a broadband signal interface configured to receive broadband radio frequency signals, and a plurality of broadband signal connections configured to distribute broadband radio frequency signals. The interface device also includes circuitry defining an upstream signal path and a downstream signal path and including a gain control circuit and a slope control circuit each positioned along the downstream signal path. The circuitry is configured to accommodate downstream transmission of the broadband signals onto twisted pair wiring.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims the benefit of U.S. Provisional PatentApplication Ser. No. 61/545,476, filed Oct. 10, 2011, which applicationis hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates generally to distribution of broadbandsignals, such as cable television signals. In particular, the presentdisclosure relates to a broadband radio frequency data communicationsystem using twisted pair wiring.

BACKGROUND

Broadband radio frequency systems, such as cable television systems,typically use coaxial cables to distribute signals from a head end to afacility, and also for wiring within any facility. At the facility,devices configured to receive broadband signals, such as televisions,set-top boxes, computing systems, or other devices, are preconfigured toreceive signals having power levels within a particular range. Forexample, analog signals received at a subscriber device are generallyrequired to be in the range of 0 to +20 dBmV, while digital signals aregenerally distributed in the range of −10 dBmV to +20 dBmV.

When broadband signals are received at a facility, they aretraditionally routed to wall outlets or other subscriber locations usingcoaxial cabling. This presents challenges to the technician/installer.This is because there are few standards for routing of coaxial cablenetworks—the lack of standards leads to many different wiringconfigurations within a facility, leading to nonstandard and unreliablecabling and loss levels at different locations within a facility. Insome cases, to address the lack of standards available in RF cabling,systems have been developed which take advantage of twisted pair wiringat a facility to deliver radio frequency signals. Use of twisted pairwiring allows installation technicians to utilize familiar designstandards to distribute signals throughout the facility.

Delivering RF signals via twisted pair wiring is not without drawbacks.For example, although layout standards are more standardized for twistedpair wiring than coaxial wiring, twisted pair wiring experiencescomparatively greater levels of loss. For example, on a 90 meter lengthof Category 6A Unshielded Twisted Pair cable, attenuation at 862 MHz isapproximately 54 dB, while a coaxial cable of equivalent length hasapproximately 18 dB attenuation. Additionally, the difference inattenuation between the highest and lowest frequencies is substantiallygreater in twisted pair media. The 90 meter twisted pair cable describedabove would have approximately 17 dB of loss at 85 MHz while an equallength of RG-6 coaxial cable has approximately 6 dB of loss. So the lossdifference between 862 MHz and 85 MHz is approximately 37 dB in twistedpair media, while it is closer to 12 dB in coaxial media.

Accordingly, greater attenuation and greater difference in attenuationbetween the highest and lowest frequencies result in twisted-pair wiringsystems having different operational requirements as compared to coaxialsystems. This is especially the case for devices designed to deliverbroadband services (e.g., cable television) over a TIA-568 CompliantTwisted Pair infrastructure. In such cases, the increased signalattenuation occurring due to transmission of broadband services overtwisted pair wiring can result in data degradation or loss if theoverall systems are not adjusted to accommodate for such attenuationlosses.

SUMMARY

In accordance with the following disclosure, the above and other issuesare addressed by the following:

In a first aspect, a broadband signal distribution interface deviceincludes a broadband signal interface configured to receive broadbandradio frequency signals, and a plurality of broadband signal connectionsconfigured to distribute broadband radio frequency signals. Thebroadband signal distribution interface device also includes circuitrydefining an upstream signal path and a downstream signal path betweenthe broadband signal interface and the plurality of broadband signalconnections, the upstream signal path defining a low frequency range andthe downstream signal path defining a high frequency range. Thecircuitry includes a gain control circuit and a slope control circuiteach positioned along the downstream signal path, wherein the circuitryis configured to accommodate downstream transmission of the broadbandsignals onto twisted pair wiring.

In a second aspect, a broadband line driver includes a broadband signalinterface configured to send and receive broadband radio frequencysignals, and a plurality of twisted pair connections, each of thetwisted pair connections configured to distribute broadband radiofrequency signals. The broadband line driver includes circuitry definingan upstream signal path and a downstream signal path communicativelyconnected to the broadband signal input interface, the upstream signalpath defining a low frequency range and the downstream signal pathdefining a high frequency range. The broadband line driver also includesa twisted pair interface circuit having an outbound signal pathconnecting one of the plurality of twisted pair connections to thedownstream signal path and an inbound signal path connecting the one ofthe plurality of twisted pair connections to the upstream signal path.The twisted pair interface circuit includes an amplifier positioned onthe outbound signal path, a radio frequency switch positioned on theinbound signal path, and a voltage monitoring circuit configured toactivate one or both of the amplifier and the radio frequency switchdepending upon an observed voltage.

In a third aspect, a method of adjusting output power of broadband radiofrequency signals on twisted pair lines includes monitoring a referencevoltage level received at a broadband line driver via a twisted pairconnection. The method includes, upon determining that the referencevoltage level exceeds a predetermined level, deactivating an amplifierconnected to a downstream path leading to the twisted pair connectionand setting a radio frequency switch connected along an upstream path toa high attenuation condition. The method also includes, upon determiningthat the reference voltage is below a second predetermined level,activating the amplifier and setting the radio frequency switch to ahigh attenuation condition The method further includes, upon determiningthat the reference voltage exceeds a third predetermined level,activating the amplifier and setting the radio frequency switch to a lowattenuation condition.

In a fourth aspect, a broadband signal distribution system useable at afacility, that includes a broadband signal distribution interface deviceand a plurality of broadband line drivers. The broadband signaldistribution interface device is configured to receive broadband radiofrequency signals from a headend and including a plurality of broadbandsignal connections, and includes circuitry defining an upstream signalpath and a downstream signal path, the circuitry including a gaincontrol circuit and a slope control circuit each positioned along thedownstream signal path, wherein the circuitry is configured toaccommodate downstream transmission of the broadband signals ontotwisted pair wiring. The broadband line drivers are communicativelycoupled to the broadband signal connections of the broadband signaldistribution interface device, and each include a plurality of twistedpair interfaces. Each twisted pair interface associated with a twistedpair interface circuit has an outbound signal path and an inbound signalpath, the twisted pair interface circuit including an amplifierpositioned on the outbound signal path and a radio frequency switchpositioned on the inbound signal path, and a voltage monitoring circuitconfigured to activate one or both of the amplifier and the radiofrequency switch depending upon an observed voltage or a signal receivedfrom an active balun device configured to receive broadband signals overtwisted pair wiring for connection to a broadband endpoint.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example twisted pair broadband radio frequencydistribution system useable at a facility, in which radio frequencysignals are passed over twisted pair wiring;

FIG. 2 is a schematic diagram illustrating wiring assignment in an RJ-45connector, with which radio frequency signals can be transmitted withina facility using a twisted pair broadband radio frequency distributionsystem;

FIG. 3 is a schematic diagram illustrating signal processing within anexample broadband radio frequency interface, according to a possibleembodiment;

FIG. 4 is a schematic diagram illustrating signal routing and adjustmentfor broadband signal repeat and amplification within a line driver usedin the twisted pair broadband radio frequency distribution system ofFIG. 1;

FIG. 5 is a schematic diagram illustrating signal routing and adjustmentfor broadband signal transfer to twisted pair wiring within a linedriver used in the twisted pair broadband radio frequency distributionsystem of FIG. 1;

FIG. 6 is a schematic diagram illustrating signal processing within aremote active balun useable in the twisted pair broadband radiofrequency distribution system of FIG. 1, which can be interfaced toradio frequency receiver within the facility; and

FIG. 7 illustrates a flowchart of operation of a line driver within abroadband radio frequency signal distribution system.

DETAILED DESCRIPTION

Various embodiments of the present invention will be described in detailwith reference to the drawings, wherein like reference numeralsrepresent like parts and assemblies throughout the several views.Reference to various embodiments does not limit the scope of theinvention, which is limited only by the scope of the claims attachedhereto. Additionally, any examples set forth in this specification arenot intended to be limiting and merely set forth some of the manypossible embodiments for the claimed invention.

In general, the present disclosure relates to an improved system fordelivering broadband radio frequency signals to endpoints at a facilityusing twisted pair wiring at the facility. The systems, devices, andmethods discussed herein provide for selective, connection-by-connectionsignal amplification, which results in power consumption on an as-neededbasis. Additionally, in certain aspects, the present disclosure providesa system that can be used concurrently with existing data communicationnetworks, over shared twisted pair wiring. Other advantages exist aswell.

Referring now to FIG. 1, an example twisted pair broadband radiofrequency distribution system 100 is shown. The system 100 is useable ata facility 10, which can be any building or set of buildings positionedin relative proximity to one another such that local cabling can beshared among the buildings, for example according to TIA-568 TwistedPair Wiring standards. The system 100 receives broadband radio frequencysignals from an upstream source 12, such as a headend or other broadbandradio frequency signal distribution source.

In the embodiment shown, the system 100 includes a broadband signaldistribution interface device 102 which receives broadband radiofrequency signals from the upstream source 12. In various embodiments,the broadband distribution interface device 102 can receive thesesignals via an optical network, a coaxial cable network, or other typesof differential signaling networks. The broadband distribution interfacedevice 102 includes a plurality of distribution connections 104, useableto distribute broadband radio frequency signals to downstream devices.In various embodiments, the distribution connections 104 can be opticalor coaxial cable connections, and may be the same type of connection asthat used by the broadband distribution interface device 102 to receivesignals from the upstream source 12.

In certain embodiments the broadband signal distribution interfacedevice 102 can include a number of features relating to adjustment ofgain and slope of signals received at the facility, to ensure that thesignals are adequately conditioned for transmission on both traditionalcoaxial as well as twisted pair wiring. Although in various embodimentsa variety of types of signal conditioning circuitry and routingcircuitry can be included in the broadband distribution interface device102, an example implementation of such circuitry is discussed below inconnection with FIG. 3.

As illustrated in FIG. 1, the system 100 also includes a plurality ofbroadband line drivers 106. The broadband line drivers 106 generallyinclude a broadband signal interface configured to send and receivebroadband radio frequency signals, for example using a coaxial oroptical cable connection. The broadband line drivers 106 each alsoinclude twisted pair connections configured to distribute broadbandradio frequency signals via a twisted pair connection, for example on anunassigned pair of a 10/100BaseT connection (e.g., the 7-8 pair of afour-pair twisted pair wire).

The broadband line drivers 106 also optionally include a plurality ofbroadband radio frequency signal distribution connections, asillustrated in further detail in FIG. 4. As shown, the broadband radiofrequency signal distribution connections allow for connection of afirst broadband line driver 106 to a second broadband line driver (shownas line drivers 106′), forming a cascaded arrangement of line drivers.In such arrangements, the broadband radio frequency signal distributionconnections of each broadband line driver 106 can have a common formatwith the broadband signal interface (e.g., providing optical or RFcoaxial cable connectivity).

Each of the broadband line drivers 106 can be interconnected to a remotebalun 108 via a twisted pair wire 110 interconnected to the twisted pairconnection of that line driver, respectively. The remote baluns 108shown in FIG. 1 generally convert differential twisted pair signals togrounded, radio frequency signals (e.g., as distributed via coaxialcabling). The remote balun 108 can be, in certain embodiments, a walloutlet-type balun or a freestanding balun, and can provide a broadbandradio frequency connection for an endpoint device configured to receivebroadband RF signals. An example of circuitry used in such a remotebalun is discussed below in connection with FIG. 6.

In the embodiments of the present disclosure, the broadband radiofrequency signals distributed within the facility 10 can take differentforms. In example embodiments, the broadband radio frequency signalsdistributed by the system are adapted to be within the range of 5 to 862MHz, representing typical bands of frequencies used to deliver cabletelevision signals. In such embodiments, remote baluns 108 can beconnected to any of a variety of types of endpoints capable of receivingand processing cable television signals, such as televisions, set topboxes, digital video recorders, or other electronic devices.

In accordance with the present disclosure, the broadband line drivers106 include circuitry for managing output power on each of the twistedpair connections associated with that line driver by sensing attenuationbetween the line driver and an remote balun 108 to which the line driveris connected by twisted pair wiring 110. Additionally, the broadbandline drivers 106 include circuitry for managing output power on each ofthe broadband radio frequency signal distribution connections, toprovide for improved cascading of line drivers within a particularfacility's twisted pair broadband radio frequency distribution system100. Additional details regarding monitoring and management of twistedpair connections at a broadband line driver are provided below inconjunction with FIGS. 5 and 7.

Referring now to FIG. 2, an example of a typical twisted pair jack 200is illustrated. The twisted pair jack 200 can be used, for example, as atwisted pair connection at a broadband line driver 106 of FIG. 1, aswell as to deliver data within a twisted pair network. In the embodimentshown, the twisted pair jack 200 is an RJ-45 jack; however, inalternative embodiments, other formats could be used as well.

In the embodiment shown, the twisted pair jack 200 includes a pluralityof pairs 202 of twisted pair wires 204. In this embodiment, four pairs202 a-d are shown, with a first pair 202 a formed from the first andsecond wires 204 a-b, a second pair 202 b formed from the third andsixth wires 204 c, 204 f, a third pair 202 c formed from the fourth andfifth wires 204 d-e, and a fourth pair 202 d formed from the seventh andeighth wires 204 g-h. The twisted pair jack 200 can be used to deliverbroadband data, for example 10BaseT or 100BaseT signals, within afacility. In such embodiments, it may be the case that certain ones ofthe pairs 202 a-d are unused. For example, in 10BaseT or 100BaseTsystems, only the first and second pairs 202 a-b are used. In suchembodiments, and in accordance with certain features disclosed herein,another pair, such as the fourth pair 202 d, could be used to transmitbroadband radio frequency signals within the facility. Additionally,other unused pairs, such as the third pair 202 c, could be used todeliver other types of services, such as power to a remote device, suchas the remote baluns 108 discussed above.

Referring now to FIG. 3, example circuitry 300 for a broadbanddistribution interface device 102 is shown. The circuitry 300 includesan upstream interface 302, illustrated as CATV interface. The upstreaminterface 302 receives broadband radio frequency signals, such as CATVsignals, on a coaxial or optical network connection. The circuitry 300also includes additional inputs, including a power input 304 (shown as a+12 volt power supply input), as well as inbound and outbound auxiliaryports 306 a-b, configured to introduce or receive upstream or downstreamsignals locally at a facility, respectively.

The circuitry 300 defines an upstream path 308 and a downstream path310. By upstream, it is intended that signals are traveling in a generaldirection toward a headend or broadband radio frequency signaldistribution source, while downstream refers to a signaling directionfrom the headend to endpoints (e.g., televisions, set top boxes, orother electronics). It is understood that not all upstream signals willtravel an entire length of a signal path from an endpoint to a headend,but may be received, filtered, and processed by a device along thatroute (such as broadband distribution interface device 102 or linedriver 106). Similarly, downstream signals need not travel an entiresignal path from a headend to an endpoint, but may be received andprocessed by a device between those components as well.

At the upstream interface 302, a frequency splitter, optionally formedfrom a high pass filter 312 and a low pass filter 314, separates signalsonto the upstream path 308 and the downstream path 310, respectively. Inthe case of broadband cable television signals, the upstream path 308will typically carry lower-frequency signals, while the downstream path310 will carry higher-frequency signals. In one embodiment, the lowerfrequency signals are in the range of 5 to 42 MHz, and the higherfrequency signals are in the range of 54 to 862 MHz. In an alternativeembodiment, the lower frequency signals are in the range of 5 to 65 MHz,and the higher frequency signals are in the range of 85 to 862 MHz.Other frequency ranges could be used as well.

The upstream path 308 and downstream path 310 are merged at a set ofhigh pass and low pass filters 316, 318, and the combined signals aretransmitted to a splitter 320, which leads to broadband signalconnections configured to distribute broadband radio frequency signalsdownstream (from the downstream path 310), and receive signals beingpassed upstream (destined for the upstream path 308). In the embodimentshown, the splitter 320 is an 8-port splitter providing 23 dB spacingbetween signals. Other splitter arrangements are possible as well.

On the upstream path, signals received from broadband signal connectionsand the splitter 320 are transmitted through a low pass filter 322 andupstream amplifier 324, and the resulting signal is returned to theupstream interface 302 via filter 312, as well as to inbound auxiliaryport 306 a.

A low band indicator 326 provides a visual indication of a power levelof the received signal, prior to amplification, to indicate a quality ofupstream data received at the broadband distribution interface device102. In the embodiment shown, the low band indicator 326 includescolored light emitting diodes indicating whether a power level isacceptable (green LED), too high (yellow LED), or too low (red LED).Other indicator arrangements are possible as well.

On the downstream path 310, signals that are transmitted remain in arelatively wide frequency band, and attenuate at different ratesdownstream of the broadband distribution interface device 102.Accordingly, the circuitry 300 provides automatic monitoring, as well asgain and slope control of such signals to ensure that output power todownstream line drivers 106 is at an appropriate level for transmissionultimately to twisted pair networks. In the embodiment shown, thedownstream path 310 includes a pilot filter 328 configured to remove anypilot signals received from upstream of the broadband distributioninterface device 102. An automatic gain control circuit 330 determinesan amount of amplification to apply across an entire frequency rangepassed along the downstream path 310, and an amplifier 332 amplifies thesignals on the downstream path according to the gain control determinedby the gain control circuit 330. An equalizer 334 connected to an outputof the amplifier 332 reduces delay variations across the frequenciespassed through the amplifier 332, as well as to flatten the gain appliedto the signals on the downstream path 310. A slope control circuit 336adjusts a slope of the signals, to ensure that the higher frequencysignals, which experience greater attenuation over both coaxial andtwisted pair wiring, are sufficiently amplified that downstream devices(e.g., broadband line drivers 106) receive relatively uniform signalsacross the desired frequency range. A high pass filter 338 removes anyremaining low frequency signals that might have been generated within orreceived by the circuitry 300 of the downstream path 310, and a secondamplifier 340 amplifies the slope-adjusted signal for transmissiondownstream through the high pass filter 316, as well as the splitter 320and subsequent broadband signal connections.

To provide continuous adjustment of the gain and slope of signals on thedownstream path 310, a feedback path following amplifier 340 is passedto a signal splitter 342, which in turn passes signals to a highfrequency sensor 344 and a low frequency signal sensor 346. A controlcircuit 348 determines the average power of the high frequency signalsand low frequency signals at the output of the amplifier 340, and canadjust the gain and slope of that signal by sending control signals tothe gain control circuit 330 and the slope control circuit 336.

Through use of the control circuit 348, as well as the gain and slopecontrol circuits 330, 336, automatic adjustment and amplification ofreceived signals is provided within the broadband distribution interfacedevice 102. The broadband distribution interface device 102 thereforeneed not require receipt of downstream signals having a sufficientlyhigh power. In certain embodiments of the present disclosure, thebroadband distribution interface device 102 is configured to be capableof receiving downstream RF signals having a power of anywhere between 0dBmV to +25 dBmV, and can automatically adjust the output power ofsignals delivered to the splitter 320, and therefore to downstreamdevices.

In the embodiment shown, a pilot tone generator 350 is communicativelyconnected to the downstream path 310 following the amplifier 340, andinjects a high-frequency tone onto the downstream line. The pilot tonecan be used by downstream devices to monitor and control the gain and RFpower at high frequencies, which typically experience the greatestamount of attenuation loss along cabling (e.g., coaxial, twisted pair,or optical). In certain embodiments, the pilot tone generator 350 isconfigured to generate a tone above a highest occupied frequency, suchas an 869 MHz pilot signal. Other tone frequencies could be used aswell.

In certain embodiments, a dedicated low frequency pilot tone could beused as well, to monitor gain and power of received signals at lowerfrequencies. However, in the embodiment shown, signal power in the lowerend of the upstream band (e.g., 5-42 or 5-65 MHz) is used to monitor andcontrol gain and power of low frequency signals.

Similar to the low band indicator 326, a high band indicator 352provides a visual indication of a power level of the received downstreamsignal, prior to amplification, to indicate a quality of downstream datareceived at the broadband distribution interface device 102. In theembodiment shown, the high band indicator 552 includes colored lightemitting diodes indicating whether a power level is acceptable (greenLED), too high (yellow LED), or too low (red LED). Other indicatorarrangements are possible as well.

Referring now to FIGS. 4-5, circuitry 400 is illustrated that can beused in a broadband line driver, such as the line drivers 106 of FIG. 1,is shown. Referring specifically to FIG. 4, the circuitry 400 includes arepeater portion 402 and a twisted pair distribution portion 404. Thecircuitry 400 also includes a power connection 406, providing power tothe circuitry 400 within the line driver 106.

The repeater portion 402 generally is configured to allow a broadbandline driver to be connected upstream of another broadband line driver,forming a cascaded arrangement of broadband line drivers which willallow for distribution of signals across a larger physical area thanwould otherwise be limited by signal attenuation over a cable length.The repeater portion 402 generally includes a broadband signal interfaceconnection 408, and is separated into an upstream path 410 and adownstream path 412.

The repeater portion 402 generally resembles the circuitry 300 of FIG.3, but lacks the pilot tone generator 350 or pilot filter 328 describedin that circuitry. Rather, a gain control circuit 414 is located at thebroadband signal interface connection 408, and before signals are splitby high pass and low pass filters 416, 418 onto the upstream anddownstream paths 410, 412. The upstream and downstream paths 410, 412are merged at a downstream end of the repeater portion at high and lowpass filters 420, 422, and the combined signal is sent to a splitter424, which distributes repeated and re-amplified broadband radiofrequency signals at a plurality of distribution connections, forexample to downstream broadband line drivers or other broadband radiofrequency devices. In the embodiment shown, the splitter 424 is a 4-portsplitter providing 23 dB spacing between signals. Other splitterarrangements are possible as well.

The upstream path 410 is analogous to that described in conjunction withFIG. 3, and includes a low pass filter 426, amplifier 428, and equalizer430, the functionality of which is analogous to that previouslydescribed. The downstream path 412 includes an amplifier 432, equalizer434, slope control circuit 436, high pass filter 438, and amplifier 440,again as described above. The upstream path 410 also includes a furtherequalizer 442 positioned immediately prior to high pass filter 416, toregulate the slope and gain of signals to be repeated onto a subsequentbroadband line driver (as opposed to signals passed onto twisted pairwiring, as discussed below).

The repeater portion 402 also includes a signal splitter 444, high andlow sense circuits 446, 448, and a control circuit 450, used to sensepower of high frequency and low frequency signals and control gain andslope of amplified signals transmitted from the line driver. In certainembodiments, the high sense circuit 446 can use the pilot tone signalgenerated by the pilot tone generator of the broadband distributioninterface device 102 to control a power level of high frequency signals.

The twisted pair distribution portion 404 includes a plurality oftwisted pair connections used to distribute broadband radio frequencysignals. In the embodiment shown, the twisted pair distribution portion404 includes a plurality of connection boards 452, each of which has aplurality of twisted pair connectors thereon. In the embodiment shown,each of six connection boards 452 has four RJ-45 connection interfacesthereon, although in alternative embodiments other numbers or types oftwisted pair connections could be used, with more or fewer connectionboards.

Each connection board 452 has an inbound path 454 and outbound path 456connected to that board, each associated with inbound and outboundsignals, respectively. In the embodiment shown, the inbound paths arejoined and passed through an amplifier 458, and merged onto the upstreampath 410 of the repeater portion 402. This allows upstream signals fromendpoints connected to the twisted pair connections to be routed back toa headend via the broadband line driver 106 and broadband distributioninterface device 102. The outbound paths 456 are connected to thedownstream path 412 of the repeater portion 402 via an amplifier 460 andequalizer 462. Additionally, a feedback path is provided from the outputof the amplifier 460 to the splitter 444 and control circuitry 450, sothe gain and slope generated by the line driver is adjusted based onobserved output power to the twisted pair connections.

Furthermore, and as discussed above in connection with the circuitry300, in certain embodiments the circuitry 400 includes indicators 464,466, which respectively indicate the power level of signals observed onthe upstream path 410 and downstream path 412.

Referring now to FIG. 5, example routing circuitry 500 forcommunicatively connecting outbound and inbound paths to a twisted pairconnection is illustrated. The routing circuitry 500 can represent, forexample, one of the four routing circuits used in each connection board452 of FIG. 4. In the embodiment shown, the routing circuitry 500provides a connection between inbound and outbound paths 502, 504,respectively, and a twisted pair connection 506, illustrated as an RJ-45port. Other types of twisted pair connections could be used as well.

Generally, the routing circuitry 500 is configured to detect a length oftwisted pair wiring used to deliver broadband radio frequency signals,and manage power levels associated with the broadband radio frequencysignals sent and received via the twisted pair connection 506. In theembodiment shown, the inbound path 502 includes a radio frequency (RF)switch 508, and is connected to a low pass filter 510. The RF switch 508selectively introduces a high or low attenuation onto the inbound line,for example in the case where the twisted pair line connected to thetwisted pair connection 506 is relatively short, resulting in lowattenuation.

The outbound path 504 includes a cable simulator 512, amplifier 514, andequalizer 516, which is in turn connected to a high pass filter 518. Thecable simulator 512 is selectively activatable to introduce additionalattenuation onto the outbound path 504, for example in the case wherethe twisted pair line connected to the twisted pair connection 506 isrelatively short, resulting in low attenuation. The amplifier 514 can beactivated or deactivated, for example to provide further amplificationbased on a detected remote balun (e.g., balun 108).

A local balun 520 positioned as an output of the merged high pass andlow pass signals transforms those signals to a differential signal on apair of twisted pair wires 521 a-b (e.g., the 7-8 wires of an 8-wiretwisted pair connection, such as an RJ-45 connection), and routes thatsignal to the twisted pair connector 506. The twisted pair connector 506introduces a power signal onto a second pair of twisted pair wires(shown as the 4-5 wires, or third pair of wires in a RJ-45 jack).Additionally, a network connector 522 merges the twisted pair connector506 with data connectivity using the two remaining pairs of a four-pairtwisted pair connector, such as would be available in a 10/100BaseTconnection.

On the pair of wires 521 a-b, a balun sensing circuit 524 and a lengthsensing circuit 526 are included to determine (1) whether a far endbalun is connected to the twisted pair connector 506, and (2) what thelength of the twisted pair wiring is, based on a determination ofattenuation from a predetermined voltage, respectively. The balunsensing circuit 524 provides a signal to the RF switch 508 and amplifier514, and the length sensing circuit 526 provides a signal to the cablesimulator. Based on a sensed voltage generated by the balun sensingcircuit 524, one or both of the RF switch 508 and amplifier 514 may beactivated or deactivated. The balun sensing circuit 524 includes a balunsensing identifier 528, which indicates visibly whether a remote balunis connected to the twisted pair wiring interconnected to the twistedpair connector 506 (for example by sensing signals on the 7-8 pair).

Furthermore, based on a sensed voltage generated by the length sensingcircuit 526, the cable simulator 512 can be activated or deactivated,thereby selectively simulating additional length of twisted pair wiringby introducing attenuation onto the outbound path 504. Operational modesof the circuitry 500, in particular as controlled by the balun sensingcircuit 524 and length sensing circuit 526, are discussed in furtherdetail below in connection with FIG. 7.

FIG. 6 is a schematic diagram illustrating circuitry 600 that can beincluded within a remote active balun, such as balun 108 of FIG. 1.Typically the balun 108 including circuitry 600 is positioned at alocation remote from the broadband line driver 106, and can be includeeither a wall outlet RF connector, or a freestanding balun elementincluding an RF connector. In either case, the circuitry 600 isconfigured to provide broadband radio frequency signals for use by anendpoint, such as a television, set top box, or other electronicequipment. The circuitry 600 provides conversion between a twisted pairconnector 602 (shown as an RJ-45 connector) and a coaxial connector 604(shown as an F-type coaxial cable television signal connector). Thecircuitry includes a twisted pair data connector 606 configured toreceive data signaling pairs of the twisted pair connector 602, such asthe 1-2 and 3-6 pairs of a four-pair connector, as well as a voltageconnection 608, which receives voltage from the 4-5 pair of the twistedpair connector 602. A connection indicator 610, shown as a lightemitting diode, is activated when power is received on the 4-5 pair,indicating that a connection to a far end line driver or other devicethat provides power and broadband signals over twisted pair wiring hasbeen established. In the embodiment shown, the 7-8 pair of signalsreceived at the twisted pair connector 602 are routed to a balun 612,which converts the signals from differential signals on the twisted pairwiring to grounded, coaxial RF signals.

Between the balun 612 and the coaxial connector 604, the circuitry isseparated into an upstream path 614 and a downstream path 616. Invarious embodiments, the upstream path 614 and downstream path 616 areseparated according to frequency, with lower frequency signals used totransmit data on the upstream path 614 and higher frequency signals usedto transmit data on the downstream path 616. Although the specificfrequency ranges included on each of the upstream path 614 anddownstream path 616 may vary, they will generally correspond to thosesame frequency ranges as implemented in the broadband line drivers 106and broadband signal distribution interface device 102. A set of highpass filters and low pass filters 615 a-b, 617-b, respectively, separatethe higher and lower frequency signals onto the respective paths 614,616.

In the embodiment shown, the downstream path 616 includes a gain controlcircuit 618, amplifier 620, and equalizer 622, used to adjust a gain,amplitude, and slope of a signal received at the balun. A high frequencysensor 624 captures a power level of a high frequency signal at anoutput of the equalizer 622, and a control circuit 626 adjusts the gaincontrol circuit 618 to automatically adjust amplification of thedownstream signal accordingly, before it is transmitted to an endpointvia the coaxial connector 604.

FIG. 7 illustrates a flowchart 700 of operation of a line driver withina broadband radio frequency signal distribution system, when connectedto a remote balun. The flowchart 700 illustrates example adjustment ofline driver circuitry, such as the routing circuitry 500 of FIG. 5, toensure port-by-port customized power adjustment for broadband signalstransmitted via twisted pair wiring. During operation, a remote balunhas a direct current feedback component that allows a test voltage to bemonitored at the line driver circuitry 500 (step 702). A voltage levelis then assessed by one or both of the balun sensing circuit 524 and thelength sensing circuit 526 (operation 704) If the monitored voltage ishigher than a predetermined threshold level, this indicates that thereis no connection between the balun and line driver. Accordingly, thecircuitry 500 in the line driver, in particular the balun sensingcircuit 524, will deactivate the downstream signal amplifier 514 and setthe RF switch 508 to a high attenuation condition, essentially shuttingoff the return path and preventing ingress of unwanted RF signals on the7-8 pair of a twisted pair cable (step 706).

If the monitored voltage is lower than a predetermined signal level,this indicates that a connection between the line driver 106 and remotebalun 108 is relatively short, and that there is only limitedattenuation occurring between those devices. Accordingly, the circuitry500 in the line driver will activate the downstream amplifier 514, butactivates the cable simulator 512, to attenuate the signal entering theamplifier 514 and prevent excess power from being delivered to thatremote balun. Additionally, the return path RF switch 508 is set to alow attenuation condition, allowing upstream signals to be transmitted(step 708).

If the monitored voltage is above a second predetermined signal level,this indicates that a long cable is connected between the line driver106 and the remote balun 108, as sensed by the length sensing circuit526. In this situation, the cable simulator 512 is deactivated, theamplifier 514 is activated, and the RF switch 508 is set to a lowattenuation condition (step 710).

After one or more actions are taken with respect to setting the signalamplifier 514, RF switch 508, or cable simulator 512, the line drivercircuitry continues to monitor voltage, in case a connectivity statebetween the line driver and a remote balun changes over time (return tostep 702).

Referring now to FIGS. 1-7 generally, it is noted that use of thetwisted pair broadband radio frequency distribution system 100 disclosedherein allows for power consumption on a port-by-port basis, whileallowing more than 65,000 radio frequency outlets to be supported (atremote baluns). Additionally, in certain aspects, the present disclosureprovides a system that can be used concurrently with existing datacommunication networks, over shared twisted pair wiring, whilepreventing ingress of other data signals onto the network componentsintended to distribute broadband radio frequency signals. Otheradvantages are realized as well, and are apparent in the implementationsdiscussed herein.

The above specification, examples and data provide a completedescription of the manufacture and use of the composition of theinvention. Since many embodiments of the invention can be made withoutdeparting from the spirit and scope of the invention, the inventionresides in the claims hereinafter appended.

What is claimed is:
 1. A broadband signal distribution interface devicecomprising: (a) a broadband signal interface configured to receivebroadband radio frequency signals; (b) a plurality of broadband signalconnections configured to distribute broadband radio frequency signals;(c) circuitry defining an upstream signal path and a downstream signalpath between the broadband signal interface and the plurality ofbroadband signal connections, the upstream signal path defining a lowfrequency range and the downstream signal path defining a high frequencyrange, the circuitry including a gain control circuit and a slopecontrol circuit each positioned along the downstream signal path,wherein the circuitry is configured to accommodate downstreamtransmission of the broadband signals onto twisted pair wiring.
 2. Thebroadband signal distribution interface device of claim 1, wherein thebroadband signal interface is a coaxial cable interface.
 3. Thebroadband signal distribution interface device of claim 1, wherein thebroadband signal interface is an optical cable interface.
 4. Thebroadband signal distribution interface device of claim 1, furthercomprising a control circuit configured to sense an output power levelof broadband radio frequency signals.
 5. The broadband signaldistribution interface device of claim 4, further comprising a pilotsignal generator providing a pilot signal on the downstream path, thepilot signal having a predetermined signal strength and useable bydownstream devices to estimate a cable length between the broadbandsignal distribution interface device and the downstream device based ona level of attenuation of the pilot signal as compared to thepredetermined signal strength.
 6. The broadband signal distributioninterface device of claim 1, further comprising an automatic indicatorplaced on at least one of the upstream signal path and the downstreamsignal path and configured to display an indication of signal strengthof broadband radio frequency signals received at the broadband signaldistribution interface device.
 7. The broadband signal distributioninterface device of claim 6, wherein the automatic indicator includesone or more light emitting diodes indicating an attenuation level ofsignals received at broadband signal input interface and at least one ofthe broadband signal connections.
 8. A broadband line driver comprising:(a) a broadband signal interface configured to send and receivebroadband radio frequency signals; (b) a plurality of twisted pairconnections, each of the twisted pair connections configured todistribute broadband radio frequency signals; (c) circuitry defining anupstream signal path and a downstream signal path communicativelyconnected to the broadband signal input interface, the upstream signalpath defining a low frequency range and the downstream signal pathdefining a high frequency range; (d) a twisted pair interface circuithaving an outbound signal path connecting one of the plurality oftwisted pair connections to the downstream signal path and an inboundsignal path connecting the one of the plurality of twisted pairconnections to the upstream signal path, the twisted pair interfacecircuit including: an amplifier positioned on the outbound signal path;a radio frequency switch positioned on the inbound signal path; and avoltage monitoring circuit configured to activate one or both of theamplifier and the radio frequency switch depending upon an observedvoltage.
 9. The broadband line driver of claim 8, further comprising acable simulator circuit positioned on the outbound signal path, thecable simulator circuit configured to selectively introduce signalattenuation on the outbound signal path.
 10. The broadband line driverof claim 8, wherein each of the plurality of twisted pair outputconnections has first, second, third, fourth, fifth, sixth, seventh, andeighth wire connections, and wherein the broadband radio frequencysignals are distributed on the seventh and eighth wire connections. 11.The broadband line driver of claim 8, further comprising an interfacecircuit associated with each of the plurality of twisted pair outputconnections.
 12. The broadband line driver of claim 8, furthercomprising a plurality of broadband radio frequency signal distributionconnections.
 13. The broadband line driver of claim 12, wherein thebroadband signal interface has a format compatible with a format of thebroadband radio frequency signal distribution connections.
 14. Thebroadband line driver of claim 8, wherein the circuitry includes a gaincontrol circuit.
 15. The broadband line driver of claim 14, wherein thecircuitry further includes a control circuit configured to automaticallycontrol the gain control circuit based on a pilot signal.
 16. Thebroadband line driver of claim 14, wherein the circuitry furtherincludes a slope control circuit positioned along the downstream signalpath.
 17. The broadband line driver of claim 16, wherein the circuitryfurther includes a control circuit configured to automatically controlthe slope control circuit based on a power level of a signal provided toa twisted pair interface circuit.
 18. The broadband line driver of claim16, wherein the signal provided to a twisted pair interface circuit andused by the control circuit has a frequency at a low end of a range ofbroadband radio frequency signals transmitted on the downstream path.19. The broadband line driver of claim 8, wherein the twisted pairinterface circuit includes a telecommunications jack interface.
 20. Thebroadband line driver of claim 19, wherein the telecommunications jackinterface includes an RJ-45 jack.
 21. A method of adjusting output powerof broadband radio frequency signals on twisted pair lines, the methodcomprising: monitoring a reference voltage level received at a broadbandline driver via a twisted pair connection; upon determining that thereference voltage level exceeds a predetermined level, deactivating anamplifier connected to a downstream path leading to the twisted pairconnection and setting a radio frequency switch connected along anupstream path to a high attenuation condition; upon determining that thereference voltage is below a second predetermined level, activating theamplifier and setting the radio frequency switch to a high attenuationcondition; and upon determining that the reference voltage exceeds athird predetermined level, activating the amplifier and setting theradio frequency switch to a low attenuation condition.
 22. The method ofclaim 21, wherein the broadband line driver has a plurality of twistedpair connections.
 23. The method of claim 22, further comprising: foreach of the plurality of twisted pair connections: monitoring areference voltage level received at a broadband line driver on twistedpair lines associated with the respective twisted pair connection; upondetermining that the reference voltage level exceeds a predeterminedlevel, deactivating an amplifier connected to a downstream path leadingto the twisted pair connection and setting a radio frequency switchconnected along an upstream path to a high attenuation condition; upondetermining that the reference voltage is below a second predeterminedlevel, activating the amplifier and setting the radio frequency switchto a high attenuation condition; and upon determining that the referencevoltage exceeds a third predetermined level, activating the amplifierand setting the radio frequency switch to a low attenuation condition.24. A broadband signal distribution system useable at a facility, thesystem comprising: a broadband signal distribution interface deviceconfigured to receive broadband radio frequency signals from a headendand including a plurality of broadband signal connections, the broadbandsignal distribution interface device including circuitry defining anupstream signal path and a downstream signal path, the circuitryincluding a gain control circuit and a slope control circuit eachpositioned along the downstream signal path, wherein the circuitry isconfigured to accommodate downstream transmission of the broadbandsignals onto twisted pair wiring; a plurality of broadband line driverscommunicatively coupled to the broadband signal connections of thebroadband signal distribution interface device, each of the plurality ofbroadband line drivers including a plurality of twisted pair interfaces,each twisted pair interface associated with a twisted pair interfacecircuit having an outbound signal path and an inbound signal path, thetwisted pair interface circuit including an amplifier positioned on theoutbound signal path and a radio frequency switch positioned on theinbound signal path, and a voltage monitoring circuit configured toactivate one or both of the amplifier and the radio frequency switchdepending upon an observed voltage or a signal received from an activebalun device configured to receive broadband signals over twisted pairwiring for connection to a broadband endpoint.
 25. The system of claim24, further comprising a second broadband line driver communicativelyconnected to one of the plurality of broadband line drivers, therebyforming a cascaded arrangement of broadband line drivers.
 26. The systemof claim 24, wherein the broadband radio frequency signals include cabletelevision signals.